Doors Open Ontario

Doors Open Ontario had another successful season! Nearly 500,000 people visited sites in communities across the province. Thanks to our sponsors, partners and volunteers for their support, and to all who participated. Stay tuned for information about next season …

Heintzman House Doors Open Markham

Heintzman House

Heintzman House is one of the oldest buildings in Markham. Originally built as an adobe brick cottage dating from the early 19th century, the house was enlarged by Colonel George Crookshank in 1817. Charles T. Heintzman, grandson of the founder of Toronto’s Heintzman Piano Company, purchased the property in the 1930s and transformed the house into its present, elegant form.

Tell us your story about this site

  • Full wheelchair access
  • Guided tours available
  • Parking
  • Washrooms

Contact info

135 Bay Thorn Drive
Markham, Ontario
Telephone: 905-944-3800, ext. 6609


Year built: 1816
Architectural style: Regency
Building type: Historical landmark, Historical house

Dates/hours open

Saturday September 7, 2019
Saturday: 10 a.m. to 4 p.m.

Heintzman House 135 Bay Thorn Drive